Wpf textblock text binding not updating


With WPF this is done easily by setting the Update Source Trigger property to Property Changed in the Binding definition, unfortunately this is not available for Silverlight.A workaround that I found for this was to add a Key Up event to the required Text Box and update the binding in code behind.In the demo, the rapidly changing data source is called Random Number Engine.It has a public property named Current, which returns a random number. When the value changes, the Property Changed event is raised so that the binding system will attempt to push that new value into a Text Block in the UI.Suppose that you have a data source where a property’s value changes very rapidly, perhaps several dozen times per second.You would not want the UI to display all of those values because it would just look like a blur.Every time the data is pushed, the time stamp is updated so that the next push will not occur until a pre-defined duration has elapsed.

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I don’t know the exact mechanism that enables this behavior, but we’re going to take advantage of it to make our binding work…User controls are a great way couple logic and XAML in an encapsulated way. A user control contrasts with a custom control in that a custom control contains no XAML. And though it says you may safely continue, it doesn’t continue safely at all. It means the binding target isn’t a dependency property!You can reuse a user control over and over and the logic is isolated from the general flow of your program. Custom control can be (and is sometimes are required to be) templated (for example, a Data Template). This is confusing to XAML developers because they are accustomed to binding to CLR properties that implement INotify Property Changed in their view models. A data binding source source CAN be a CLR-type property.property in WPF is extremely handy, because it is automatically inherited by all children of the element where you assign it; therefore you don’t need to set it again on each element you want to bind.However, in some cases the is not accessible: it happens for elements that are not part of the visual or logical tree.It would be better to govern how often the binding source’s new values are pushed to the binding target. One solution is to create a value converter which governs the data flow between source and target.

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